منابع مشابه
The Reactions of Cerianthus to Light
1. When Cerianthus membranaceus is illuminated upon one side, the animal turns its anterior portion toward the source of light. The number of degrees through which the animal turns is proportional to the logarithm of the intensity of the light. 2. A light intensity of between 250 m.c. and 15,000 m.c. is necessary to cause retraction of the animal. 3. The part of the spectrum which is most effec...
متن کاملDevelopmental effects of bioaccumulated selenium in eggs and larvae of two salmonid species.
Elevated concentrations of Se have been detected in cold, flowing water habitats near uranium and coal mines in Canada. Fish from these systems have concentrations of Se in their tissues that exceed toxic effect thresholds that have been established for warm-water fishes. However, the applicability of toxic effect thresholds and guidelines to cold water, lotic habitats is a matter of contention...
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Emotional reactions to basic, artificial, yet carefully controllable point-light displays (PLDs) were investigated with ratings of valence, arousal, approachability, and dominance. PLDs were varied by movement location (upper and lower) and intensity (10°, 20°, and 30° angular change) for angular upward and downward movements. Half of participants (N = 28) were told that PLDs were related to fa...
متن کاملThe light reactions of photosynthesis.
Historically, the role of light in photosynthesis has been ascribed either to a photolysis of carbon dioxide or to a photolysis of water and a resultant rearrangement of constituent atoms into molecules of oxygen and glucose (or formaldehyde). The discovery of photophosphorylation demonstrated that photosynthesis includes a light-induced phosphorus metabolism that precedes, and is independent f...
متن کاملThe Reactions of Cerianthus to Light by Mary
I t has long been known that direct sunlight (1) will cause Cerianthus membranaceus to withdraw its tentacles and body within the sheath which in nature lies beneath the sandy bottom of the sea. On the other hand, a relatively weak light causes prompt heliotropic turning toward the source of light. Since light increases the muscle tone of these animals it is apparent that light as strong as sun...
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ژورنال
عنوان ژورنال: Journal of Experimental Biology
سال: 1957
ISSN: 1477-9145,0022-0949
DOI: 10.1242/jeb.34.3.402